JimmyT wrote:
I think once one approach is successful, other approaches will have a lot of problems getting funding. Particularly if they are inherently more expensive to begin with. So the first technology to cross the finish line will have exclusivity for a long time.

I would expect the opposite, because if fusion is proven to work(or at least break-even).
without multi-billion investment, then a lot of investors will start crawling for this pie (which is not truth at the moment of speaking),

As usually happens not all of them will be accommodated by the original inventor, so its likely they will invest into alternative approaches, even if they are more expensive and/or more problematic.

If you see in industry there is always some options for each type of solution each with its advantages and disadvantages.
An example – how many types of persistent data storage do you know?

If FF fails to work, a lot of others will take the lead, but even if somebody else succeeds faster, FF can still cross the finish line successfully and find its own niche,